Bacteriological assessment of chlorinated and non-chlorinated water in Morogoro Municipality, Tanzania
This cross sectional study was conducted to assess the bacterial contamination in chlorinated and nonchlorinated water in Morogoro Municipality from October 2013 – January 2014. Fifty two samples were collected from selected taps (chlorinated samples) and directly from the water sources (non -chlorinated samples). The total viable count (TVC) was performed on nutrient agar while the total coliform count (TCC) was done by Most Probable Number (MPN) using MacConkey broth. It was found that the TVC ranged between 530 CFU/100 mL and 600 CFU/100 mL during dry season and the same range during rainy season. The TVC ranged between 530 CFU/100 mL and 600 CFU/100 mL during dry season and 600 CFU/100 mL to 650 CFU/100 mL during rainy season. The results for TCC positive chlorinated samples during dry season ranged between 3.6/100 mL and 150/100 mL while during the rainy season it ranged between 15/100 mL and 150/100 mL. The highest TCC were found at Department of Animal Science and Production in both season for chlorinated water and 41% of non- chlorinated water during dry season while all the samples of nonchlorinated water during rainy season had high TCC count. Also the results further showed that TCC for positive non- chlorinated samples during dry season ranged between 210/100 mL and >1100/100 mL while it was >1100/100 mL during rainy season. In chlorinated water, significant difference (p=0.332) was observed when TVC during dry season was compared with that of rainy season. Based on the results of this study, it is concluded that chlorinated and non- chlorinated water show high number of TCC than that recommended by WHO and Tanzania Bureau of Standards (TBS). However, there was low TVC which was within recommended standards. The high TCC observed in treated water in this study may pose a risk of acquiring water-borne diseases to the Morogoro community.
Keywords: Bacteria, coliform, tap water, Morogoro Municipality.